<template>
  <el-color-picker
    v-model="theme"
    :predefine="['#409EFF', '#1890ff', '#304156','#212121','#11a983', '#13c2c2', '#6959CD', '#f5222d', ]"
    class="theme-picker"
    popper-class="theme-picker-dropdown"
  />
</template>

<script>
const version = require('element-ui/package.json').version // element-ui version from node_modules
const ORIGINAL_THEME = '#409EFF' // default color

export default {
  data() {
    return {
      chalk: '', // content of theme-chalk css
      theme: ''
    }
  },
  computed: {
    // defaultTheme() {
    //   return this.$store.state.settings.theme
    // }
  },
  watch: {
    // defaultTheme: {
    //   handler: function(val, oldVal) {
    //     this.theme = val
    //   },
    //   immediate: true
    // },
    // async theme(val) {
    //   const oldVal = this.chalk ? this.theme : ORIGINAL_THEME
    //   if (typeof val !== 'string') return
    //   const themeCluster = this.getThemeCluster(val.replace('#', ''))
    //   const originalCluster = this.getThemeCluster(oldVal.replace('#', ''))
    //   console.log(themeCluster, originalCluster)

    //   const $message = this.$message({
    //     message: '  Compiling the theme',
    //     customClass: 'theme-message',
    //     type: 'success',
    //     duration: 0,
    //     iconClass: 'el-icon-loading'
    //   })

    //   const getHandler = (variable, id) => {
    //     return () => {
    //       const originalCluster = this.getThemeCluster(ORIGINAL_THEME.replace('#', ''))
    //       const newStyle = this.updateStyle(this[variable], originalCluster, themeCluster)

    //       let styleTag = document.getElementById(id)
    //       if (!styleTag) {
    //         styleTag = document.createElement('style')
    //         styleTag.setAttribute('id', id)
    //         document.head.appendChild(styleTag)
    //       }
    //       styleTag.innerText = newStyle
    //     }
    //   }

    //   if (!this.chalk) {
    //     const url = `https://unpkg.com/element-ui@${version}/lib/theme-chalk/index.css`
    //     await this.getCSSString(url, 'chalk')
    //   }

    //   const chalkHandler = getHandler('chalk', 'chalk-style')

    //   chalkHandler()

    //   const styles = [].slice.call(document.querySelectorAll('style'))
    //     .filter(style => {
    //       const text = style.innerText
    //       return new RegExp(oldVal, 'i').test(text) && !/Chalk Variables/.test(text)
    //     })
    //   styles.forEach(style => {
    //     const { innerText } = style
    //     if (typeof innerText !== 'string') return
    //     style.innerText = this.updateStyle(innerText, originalCluster, themeCluster)
    //   })

    //   this.$emit('change', val)

    //   $message.close()
    // }
  },

  methods: {
    updateStyle(style, oldCluster, newCluster) {
      let newStyle = style
      oldCluster.forEach((color, index) => {
        newStyle = newStyle.replace(new RegExp(color, 'ig'), newCluster[index])
      })
      return newStyle
    },

    getCSSString(url, variable) {
      return new Promise(resolve => {
        const xhr = new XMLHttpRequest()
        xhr.onreadystatechange = () => {
          if (xhr.readyState === 4 && xhr.status === 200) {
            this[variable] = xhr.responseText.replace(/@font-face{[^}]+}/, '')
            resolve()
          }
        }
        xhr.open('GET', url)
        xhr.send()
      })
    },

    getThemeCluster(theme) {
      const tintColor = (color, tint) => {
        let red = parseInt(color.slice(0, 2), 16)
        let green = parseInt(color.slice(2, 4), 16)
        let blue = parseInt(color.slice(4, 6), 16)

        if (tint === 0) { // when primary color is in its rgb space
          return [red, green, blue].join(',')
        } else {
          red += Math.round(tint * (255 - red))
          green += Math.round(tint * (255 - green))
          blue += Math.round(tint * (255 - blue))

          red = red.toString(16)
          green = green.toString(16)
          blue = blue.toString(16)

          return `#${red}${green}${blue}`
        }
      }

      const shadeColor = (color, shade) => {
        let red = parseInt(color.slice(0, 2), 16)
        let green = parseInt(color.slice(2, 4), 16)
        let blue = parseInt(color.slice(4, 6), 16)

        red = Math.round((1 - shade) * red)
        green = Math.round((1 - shade) * green)
        blue = Math.round((1 - shade) * blue)

        red = red.toString(16)
        green = green.toString(16)
        blue = blue.toString(16)

        return `#${red}${green}${blue}`
      }

      const clusters = [theme]
      for (let i = 0; i <= 9; i++) {
        clusters.push(tintColor(theme, Number((i / 10).toFixed(2))))
      }
      clusters.push(shadeColor(theme, 0.1))
      return clusters
    }
  }
}
</script>

<style>
.theme-message,
.theme-picker-dropdown {
  z-index: 99999 !important;
}

.theme-picker .el-color-picker__trigger {
  height: 26px !important;
  width: 26px !important;
  padding: 2px;
}

.theme-picker-dropdown .el-color-dropdown__link-btn {
  display: none;
}
</style>
